This invention relates to a method and a system of tracking movement of a group of people in an area so that when a person in the group is detected to have a physical condition, the person may be located.
The severe acute respiratory syndrome (SARS) is an infectious disease. People who are suspected of having contracted SARS needs to be urgently identified, located and isolated to prevent the spreading of the disease to other people. One of the symptoms of SARS is fever. Consequently, it has become important for monitoring the body temperature of people to determine if they run a temperature, i.e. they have a fever.
Typically, people visiting a building such as an office building or a hospital are required to have their body temperatures taken at the entrance of the building. If the body temperature of a particular person is found to be above a pre-determined threshold, the person may be barred from entering the building, and may be asked instead to consult a doctor. Such a one-time measurement of body temperature may not be ideal.
For example, a person may have a normal body temperature when entering the building. However, the person may subsequently develop a fever after entering the building. And if the person has contracted the SARS virus and remains in the building for hours, he may potentially infect the other people in the building by passing the virus to them. Such a situation may result in a large cluster of SARS infected people and thus poses a serious health threat.
Another reason why a one-time measurement of body temperature is not ideal is because not everyone has the exact same temperature. The normal body temperature of a person varies depending on age, gender, recent activity, food and fluid consumption, time of day, etc., and for women, the stage of a menstrual cycle. The body temperature of a person at a particular time also varies when taken from different parts of the body. A normal body temperature can range from 36.5° C. to 37.2° C. However, a threshold of 37.8° C. is often used for deciding if a person has fever. The use of such a fixed threshold is not ideal because about 5% of the population is known to have a body temperature that falls outside the normal range. Using the single fixed threshold to gauge if a person has fever will cause those having a body temperature higher than that in the range to be wrongly diagnosed to have fever, thereby causing them unnecessary inconvenience and distress. What may be worse is that using such a fixed threshold may not be able to detect fever in people with a normal temperature lower than that in the range. In other words, real cases of fever may not be detectable.